Process for the production of products containing cellulose and alkylcellulose



Patented Feb. 19, 1924.

UNITED STATES PATENT orrlcrz.

ERNST BERL, F DARMSTADT, GERMANY.

PROCESS FOR THE PRODUCTION OF PRODUCTS CONTKINING CELLULOSE AND ALKYLCELLULOSE.

No Drawing.

' from ammoniacal solution of copper oxyde or from xanthogenate-solutions, show the inconvenience of a more or less great sensibility against water. The resistance to tearing in these products is considerably less if they are at the moist state than if the are at the dry state, the hygroscopicity eing considerably increased at the same time. Products which are made from alkylcelluloses as methyl-, ethyl, benzylcellulose and their homologues possess the inconvenience of bad colourability with aqueous solutions of colouring-matter.

It has been found that products with prominent qualities, which do not possess tained if they are composed of mixtures of cellulose precipitated secondarily and of alkylcellulose. One method consists for instance in adding, at the production of artificial silk from nitro-cellulose alkylcellulose to the colloidal solution of the nitro-celhr' lose for instance a colloidal solution in alcohol, ether or acetone or glacial acetic acid, the alkylcellulose being preferably in the form of a colloidal solution with dissolvants which are mixable with the dissolvants of the nitro-cellulose. The products obtained from this mixture and freed by de-nitration in the well known manner of the nitricacid contained in the same, the said products consisting of threads, films or, the-like, possess in comparison with the cellulose set free in the manner hitherto used, a considerably increased resistance, to water and in comparisonwith the products which consist of pure alkylcellulose, a much greater colour-ability. The physical properties of the products are the above mentioned inconveniences, are ob- Application filed. October 6, 1922. Serial No. 592,841.

also favorably influenced by the process. Amongst other advantages with regard to ductility and to the specific. weight are obtained, it being possible to make the latter almost like that of natural silk.

Emamples.

1. A quantity of ethylcellulose dissolved in alcohol, which is equal to 25-7 5% of the weight. of the dry nitro-cellulose is added to a colloidal solution of nitro-cellulose in ether-alcohol. After homogenous mixing and filtration the collodial solution is spun to artificial silk threads after the dry or moist spinning process; The threads produced are freed of the nitrogen contained in them with the aid of sulphydrate solutions.

2. A colloidal solution of acetyl-cellulose in acetone is added to a colloidal solution of benzylcellulose in acetone and mixed homogenously. The viscous mass produced is treated in the well known manner to produce films. The films treated with an aqueous or weakly alcoholic alkali-solution in order to saponify the cellulose acetate, consist of a mixture of alkylcellulose and more or less completely saponified acetyl-cellulose.

I claim:

1. Process for the production of products containing cellulose and alkylcellulose con? sisting in transforming into a colloidal solution cellulose esters and alkylcellulose with the aid of dissolvants, and in treating the products produced from the mixture with substances for the conversion of the cellulose esters into cellulose.

2. Process for the production of products containing cellulose and alkylcellulose consisting in transforming cellulose esters and alkvlcellulose with the aid of dissolvants treating the products from the mixture with containing cellulose and alkylcellulose consubstances for the conversion of the cellulose sist-ing in transforming into a colloidal soluesters int-o cellulose. tion nitro cellulose and alkylcellulose with 1 4. Process for the production of products the aid of dissolvants, in spinning the mix- 5 containing cellulose and alkylcellulose conture to artificial silk threads, and in desisting in transforming into a colloidal sonitrating the latter. lution nitro cellulose and alkylcellulose with In testimony whereof I have affixed my the aid of dissolvants and in treating the signature in presence of two Witnesses. products from the mixture with substances PROF. DR. ERNST BERL.

10 for the conversion of the cellulose esters into Vitnesses:

cellulose. a T. H. ANDERSON, 5. Process for the production of products BASIL E. SAVARD. 

